Soak the morels, dried yellow fungus and bamboo pith in a bowl of water for 30 minutes. Drain.
Cut the winter melon in half with a saw-toothed edge. Scoop out the seeds.
Blanch the morels, dried yellow fungus and bamboo and set aside. Then blanch the scallops and prawns.
Mix all the seasonings to prepare a stock. Put all the ingredients into the winter melon and fill it with the stock until 80% full. Cover with plastic wrap and simmer it for about 45 minutes. Add the crab meat to serve.